Genome Evolution of the Malaria Parasite Plaasmodium falciparum
Malaria-endemic countries eastern hemisphere-CDC.png Phenom-Malaria-parasite-631.jpg Anopheles albimanus mosquito.jpg Malaria is a potentially fatal blood disease in which a parasitic protozoan (from the genus Plasmodium) is transmitted from the Anopheles mosquito to humans. "Malaria" comes from the Italian word mala ''meaning "bad" and ''aria ''meaning "air" as individuals thought the disease originated from the foul air in marshy areas (1). In 1880, the incorrect cause of the disease was changed when scientists discovered that the ''Anopheles ''mosquito was the vector between ''Plasmodium ''and humans. Malaria can also be transmitted from person-to-person through the bite of the female '' ''mosquito. Transmission Malaria is tranmitted exclusively from the bite of the ''Anopheles ''female mosquito. Factors that affect the virulence and pathogenicity of the disease are the specific species of parasite, the vector, the human host, and the environment. Difference species of the ''Anopheles ''mosquito have different abilities in regards to levels of virulence and pathogenicity. Because the species of mosquito that lives in Africa has a long lifespan and a strong human-biting necessity, 90% of the world's malaria deaths occur in Africa (2). Humans can be non-immune, semi-immune, and immune to this disease. Semi-immunity can be developed over years of exposure and is useful in preventing the risk that being infected causes severe disease. Individuals who move from locations where malaria is not as prevalent to areas where malaria is more prevalent are at risk as thse indivduals do not possess any immunity to the parasite and therefore making them more susceptible. Climatic conditions also affect the pathogenicity of the parasite as well. Rainfall patterns, temperature, and humidity all are variables that affect the lifespan of the mosquitos. Symptoms of Malaria Malaria is an acute febrile illness . In individuals who have no immunity, fever, headache, chills and vomiting are symptoms that begin to show 10-15 days after the person was bitten. ''P. falciparum ''can progress to death if not treated within 24 hours. In addition to the aforementioned symptoms, infected children often experience severe anemia , respiratory distress , or cerebral malaria . Genome Evolution in Malaria ''Plasmodium falciparum ''has evolved to become resistant to the drugs that are used to treat malaria like chloroquine and sulfadoxine-pyrimethamine (SP). In a study conducted by Daniel C. Jeffares and team, they took shotgun sequencing of a Ghanaian clinical isolate, the IT Laboratory isolate, and the chimpanzee parasite ''P. reichenowi, ''and compared them to a fully sequenced clone. According to the study, the most profound and essential features of ''P. falciparum ''were the fact that it is polymorphic and it can adaptively evolve regarding gene function, transcription, protein expression, and cellular localisation (3). Because of the aforementioned features, it was concluded that primary evolution occured in ''P. falciparum since the time when ''P. falciparum ''and ''P. reichenowi ''underwent speciation . Recently, it was determined that resistance to artemisinins have been detected in four countries: Cambodia, Myanmar, Thiland, and Vietnam. The major reason for resistance to these antimalaria drugs is due to the fact that oral artemisinins are administered alone as a sole form of treatment, and the individuals who suffer from malaria fail to fully finish the treatment once the symptoms disappear. Because of this, patients still have the parasite in their blood, and these parsites are now resistant to the drug as they had survived an unfinished treatment, and they reproduce, spreading the resistance. Prevention and Eradication According to Hadyn Perry's TED talk, essential factors of an antimalaria treatment must be: safe to humans, it must not have a lasting impact on the environment, cost effective because many of the countries involved have emerging markets, and species specific to the mosquito that transmits malaria (Anopheles) because other insects are beneficial to the ecosystem (4). Because only female mosquitos only bite and male mosquitos are bound to find a female to mate, if the male mosquito has a gene in which the offspring do not survive, then there will not be offspring to spread the disease. Malaria Facts and Statistics According to the World Health Organization (WHO) (2): In 2012, malaria caused an estimated 627,000 deaths, taking mostly African children as victims. A child dies every minute from this treatable and curable disease. There were about 207 million cases of malaria in 2012. Fortunately, malaria mortality rates have fallen by 45% globally since 2000, and by 49% in the WHO African Region (the region with the highest prevalence). And mortality rates among children in Africa have been reduced by about 54% since 2000. Four species cause malaria in humans: ''Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, ''and ''Plasmodium ovale. '' ''Plasmodium falciparum ''causes the most deadly form of the disease. Monkeys can also be infected with malaria. Bibliography (1) http://www.medicalnewstoday.com/articles/150670.php (2) http://www.who.int/mediacentre/factsheets/fs094/en/index.html (3)http://www.ncbi.nlm.nih.gov/pubmed/17159978 and http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2663918/ (4) http://www.ted.com/talks/hadyn_parry_re_engineering_mosquitos_to_fight_disease.html